// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.chrome.browser.widget;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.ViewPropertyAnimatorListenerAdapter;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.view.animation.Interpolator;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import org.chromium.base.ApiCompatibilityUtils;
import org.chromium.chrome.R;
/**
* Layout which uses a {@link android.widget.TextView} to show a floating label above an
* {@link android.widget.EditText} when the hint is hidden due to the user inputting text.
*
* @see <a href="https://dribbble.com/shots/1254439--GIF-Mobile-Form-Interaction">Matt D. Smith on Dribble</a>
* @see <a href="http://bradfrostweb.com/blog/post/float-label-pattern/">Brad Frost's blog post</a>
*
* This class was originally written by Chris Banes; it should be replaced if/when floating labels
* are available in the support library.
* @see https://gist.github.com/chrisbanes/11247418
*
* Example XML layout:
* <org.chromium.chrome.browser.widget.FloatLabelLayout
* android:layout_width="match_parent"
* android:layout_height="wrap_content"
* app:floatLabelTextAppearance="@style/TextAppearance.YourApp.FloatLabel">
* <EditText
* android:id="@+id/edit_username"
* android:layout_width="match_parent"
* android:layout_height="wrap_content"
* android:hint="@string/account_username_hint" />
* </org.chromium.chrome.browser.widget.FloatLabelLayout>
*/
public class FloatLabelLayout extends LinearLayout {
private static final long ANIMATION_DURATION = 150;
private static final float DEFAULT_LABEL_PADDING_LEFT = 3f;
private static final float DEFAULT_LABEL_PADDING_TOP = 4f;
private static final float DEFAULT_LABEL_PADDING_RIGHT = 3f;
private static final float DEFAULT_LABEL_PADDING_BOTTOM = 4f;
private EditText mEditText;
private TextView mLabel;
private CharSequence mHint;
private Interpolator mInterpolator;
public FloatLabelLayout(Context context) {
this(context, null);
}
public FloatLabelLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public FloatLabelLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setOrientation(VERTICAL);
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FloatLabelLayout);
int leftPadding = a.getDimensionPixelSize(
R.styleable.FloatLabelLayout_floatLabelPaddingLeft,
dipsToPix(DEFAULT_LABEL_PADDING_LEFT));
int topPadding = a.getDimensionPixelSize(
R.styleable.FloatLabelLayout_floatLabelPaddingTop,
dipsToPix(DEFAULT_LABEL_PADDING_TOP));
int rightPadding = a.getDimensionPixelSize(
R.styleable.FloatLabelLayout_floatLabelPaddingRight,
dipsToPix(DEFAULT_LABEL_PADDING_RIGHT));
int bottomPadding = a.getDimensionPixelSize(
R.styleable.FloatLabelLayout_floatLabelPaddingBottom,
dipsToPix(DEFAULT_LABEL_PADDING_BOTTOM));
mHint = a.getText(R.styleable.FloatLabelLayout_floatLabelHint);
mLabel = new TextView(context);
mLabel.setPadding(leftPadding, topPadding, rightPadding, bottomPadding);
mLabel.setVisibility(INVISIBLE);
mLabel.setText(mHint);
mLabel.setFocusable(true);
ViewCompat.setPivotX(mLabel, 0f);
ViewCompat.setPivotY(mLabel, 0f);
ApiCompatibilityUtils.setTextAppearance(mLabel,
a.getResourceId(R.styleable.FloatLabelLayout_floatLabelTextAppearance,
android.R.style.TextAppearance_Small));
a.recycle();
addView(mLabel, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
mInterpolator = AnimationUtils.loadInterpolator(context,
Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP
? android.R.interpolator.fast_out_slow_in
: android.R.anim.decelerate_interpolator);
}
@Override
public final void addView(View child, int index, ViewGroup.LayoutParams params) {
if (child instanceof EditText) {
setEditText((EditText) child);
}
// Carry on adding the View...
super.addView(child, index, params);
}
/**
* Focuses the EditText and makes the label visible without the normal
* animation that occurs on focus. This is particularly useful when
* auto-focusing the first field on a form.
*/
public void focusWithoutAnimation() {
mEditText.setHint(null);
mLabel.setVisibility(View.VISIBLE);
mEditText.requestFocus();
}
private void setEditText(EditText editText) {
// If we already have an EditText, throw an exception
if (mEditText != null) {
throw new IllegalArgumentException("We already have an EditText, can only have one");
}
mEditText = editText;
// Update the label visibility with no animation
updateLabelVisibility(false);
// Add a TextWatcher so that we know when the text input has changed
mEditText.addTextChangedListener(new TextWatcher() {
@Override
public void afterTextChanged(Editable s) {
updateLabelVisibility(true);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {}
});
// Add focus listener to the EditText so that we can notify the label that it is activated.
// Allows the use of a ColorStateList for the text color on the label
mEditText.setOnFocusChangeListener(new OnFocusChangeListener() {
@Override
public void onFocusChange(View view, boolean focused) {
updateLabelVisibility(true);
}
});
// If we do not have a valid hint, try and retrieve it from the EditText
if (TextUtils.isEmpty(mHint)) {
setHint(mEditText.getHint());
}
// If we do not have a valid content description, set it to the hint text.
if (TextUtils.isEmpty(mEditText.getContentDescription())) {
mEditText.setContentDescription(mHint);
}
}
private void updateLabelVisibility(boolean animate) {
boolean hasText = !TextUtils.isEmpty(mEditText.getText());
boolean isFocused = mEditText.isFocused();
mLabel.setActivated(isFocused);
if (hasText || isFocused) {
// We should be showing the label so do so if it isn't already
if (mLabel.getVisibility() != VISIBLE) {
showLabel(animate);
}
} else {
// We should not be showing the label so hide it
if (mLabel.getVisibility() == VISIBLE) {
hideLabel(animate);
}
}
}
/**
* @return the {@link android.widget.EditText} text input
*/
public EditText getEditText() {
return mEditText;
}
/**
* @return the {@link android.widget.TextView} label
*/
public TextView getLabel() {
return mLabel;
}
/**
* Set the hint to be displayed in the floating label
*/
public void setHint(CharSequence hint) {
mHint = hint;
mLabel.setText(hint);
}
/**
* Sets the EditText text and shows the floating label without animation. To set the EditText
* text with animation, use getEditText().setText().
*
* @param text The text to display in EditText.
*/
public void setText(CharSequence text) {
showLabel(false);
mEditText.setText(text);
}
/**
* Show the label
*/
private void showLabel(boolean animate) {
if (animate) {
mLabel.setVisibility(View.VISIBLE);
ViewCompat.setTranslationY(mLabel, mLabel.getHeight());
float scale = mEditText.getTextSize() / mLabel.getTextSize();
ViewCompat.setScaleX(mLabel, scale);
ViewCompat.setScaleY(mLabel, scale);
ViewCompat.animate(mLabel)
.translationY(0f)
.scaleY(1f)
.scaleX(1f)
.setDuration(ANIMATION_DURATION)
.setListener(null)
.setInterpolator(mInterpolator).start();
} else {
mLabel.setVisibility(VISIBLE);
}
mEditText.setHint(null);
}
/**
* Hide the label
*/
private void hideLabel(boolean animate) {
if (animate) {
float scale = mEditText.getTextSize() / mLabel.getTextSize();
ViewCompat.setScaleX(mLabel, 1f);
ViewCompat.setScaleY(mLabel, 1f);
ViewCompat.setTranslationY(mLabel, 0f);
ViewCompat.animate(mLabel)
.translationY(mLabel.getHeight())
.setDuration(ANIMATION_DURATION)
.scaleX(scale)
.scaleY(scale)
.setListener(new ViewPropertyAnimatorListenerAdapter() {
@Override
public void onAnimationEnd(View view) {
mLabel.setVisibility(INVISIBLE);
mEditText.setHint(mHint);
}
})
.setInterpolator(mInterpolator).start();
} else {
mLabel.setVisibility(INVISIBLE);
mEditText.setHint(mHint);
}
}
/**
* Helper method to convert dips to pixels.
*/
private int dipsToPix(float dps) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dps,
getResources().getDisplayMetrics());
}
}